The prevalence of freshwater flocculation in cold regions: a case study from the Mackenzie River Delta, Northwest Territories
ABSTRACT. The Mackenzie River Delta (MRD) is used as a case study for evaluating the extent to which flocculation may play an important role in the transport of sediment and associated contaminants in arctic regions. Samples were collected for nondestructive analysis of particle/floc size, major ion...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1998
|
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.546.8148 http://pubs.aina.ucalgary.ca/arctic/Arctic51-2-155.pdf |
| Summary: | ABSTRACT. The Mackenzie River Delta (MRD) is used as a case study for evaluating the extent to which flocculation may play an important role in the transport of sediment and associated contaminants in arctic regions. Samples were collected for nondestructive analysis of particle/floc size, major ions, particulate organic carbon (POC), dissolved organic carbon (DOC), bacterial counts, and suspended solid (SS) concentrations. On-site measurements were made for pH, conductivity, and temperature. Results indicate that the dominant form of sediment transport to and within the MRD is flocs, and not traditionally sized primary particles. It is shown that the flocs of the Mackenzie Delta are at times larger in size than those in southern Ontario rivers that have been studied. The sediment distributions were bimodal in nature; the particle-deficient zone potentially represented a preferential particle size for flocculation. Spatial and temporal trends in the grain-size distributions suggest site-specific controlling factors of flocculation, such as source area and sediment characteristics. It is hypothesized that water temperature, suspended solid concentration, and bacteria are the important factors in controlling flocculation within the Delta. Key words: flocculation, suspended sediment, grain-size distribution, bacteria, transport RÉSUMÉ. Le delta du Mackenzie (DM) sert d’étude de cas pour déterminer l’importance du rôle que peut jouer la floculation dans le transport des sédiments et contaminants connexes dans les régions arctiques. On a recueilli des échantillons pour analyse non destructive de la taille des particules/flocons, des ions majeurs, du carbone organique particulaire (COP), du carbone organique dissous (COD), de la numération bactérienne et des concentrations solides en suspension. Les mesures du pH, de la |
|---|